Anthony mentioned he has a Web app, so that TTL trick won't work reliably.
The low TTL would be seen by servers "throughout the rest of the world" but
TTL are ignored by most clients (and many proxy servers), so all existing
users (and users that share such proxies) will be stuck on the downed
server. Check out:

for details. IMO for failover you are better off putting both servers at the
same site, using local load balancing (there are some very cost effective
solutions available now) and redundant power and Internet connections.


----- Original Message -----
From: "Greg Maccarone"
To: "Anthony Wilkins"
Sent: Tuesday, October 12, 2004 11:46 AM
Subject: Re: DNS Failover

> On Tue, 12 Oct 2004 11:01:45 +0200, Anthony Wilkins
> wrote:
>> Hi, is there anybody who can help me in finding a solution to a problem
>> I have?
>> My web server is sometime temporarily down and I want people to go to my
>> remote site where I have a backup web server. Can I change DNS on the
>> Internet fast enough for incoming requests to be handled by my redundant
>> web server? Normally I don't want traffic to go to the remote site.
>> Thanks, Anthony W.

> A way this could be achieved with DNS is to have a low TTL on the host
> entry that could be changing because of the outage. Then in most
> cases it would take no longer than the specified TTL for the changes
> to be seen throughout the rest of the world.
> my $.02.
> --
> Greg Maccarone